Devastation. James Nachtwey’s pictures from Japan

When the earthquake struck Japan on 2:46 p.m. JST Friday, March 11, TIME photographer James Nachtwey was at home in Thailand. In less than 48 hours, he arrived in Japan and made his way north of Sendai to Kesennuma City, where he began documenting the catastrophic devastation while under the looming fear of possible nuclear contamination. In a conversation during the assignment, Nachtwey described what he saw.